Hmm ... bad at sensing other people's emotions?
I think a couple other people in this thread have said this, but no, I'm not bad at sensing other people's emotions - I just give little credence to them.
Where this most often comes up is in arguments. My approach to any argument is always logical, and I treat the other person's ego as much as an object of scrutiny as the argument itself. If I notice a person is arguing completely illogically about x subject, I'll first point out all the logical flaws and contradictions in their argument, and then I'll point out that this is obviously an emotionally charged subject for them, and often suggest a source for this emotion (if I know of a likely one). No easier way to infuriate somebody!
But the point is I quickly detect the emotional centres of the argument, as they're the parts most likely to produce in terms of logic incoherent gibberish. My lack of concern for the feelings behind these is rooted in the fact that most of the time when people are arguing about something their offended feelings are essentially narcissistic. People tend to hate other people, other concepts, other groups, based most often on a personal offence to their ego, outside the bounds of logic. Many people argue not out of a concern for truth, but out of a desire to solidify their ego. I do this also - but I often afterwards realize I've done it, and garner a greater self-knowledge, which is the only way any of us can approach truth.
My feeling is that if one allows one's perception to be driven by one's emotional wishes, one is ultimately blinding oneself to truth. This is bad enough on its own, insofar as it's an offence to Truth, which is a concept I think any intelligent INTP cares very strongly about, but it's also bad insofar as being unaware of the *source* of one's emotions leads to one being controlled by them. See King Lear, which is paramount to a parable about wishful emotions versus logic and Truth.
Logic is a force that stands outside people's egotistical wishes. Only on logic can true justice be founded. And logic and justice to large extent requires subordination of a variety of negative selfish emotions, of which the average individual is full.
That said, I've been talking about disputes and arguments, of which daily life is full. The other side of the coin is relationships. And I have no patience with INTPs who have no sensitivity towards the emotional needs of their partners. If they lose their partners because of this, it's deserved (something I myself have suffered in the past). INTPs are as emotional as any other type - our biggest pitfall is assuming we're always logical and correct, whereas in reality we're often driven not by logic but by our emotions; logic is often merely a weapon we wield for our own ends. Understanding our own emotions and the emotions of the people we care about is an incredibly important job for the INTP, and any INTP who disregards developing empathy for those who deserve it deserves contempt in my eyes.
) than a solid hypothesis. Still, I do agree that INTP have trouble sorting out their own emotions. From my experience I can say that I reach a dead end trying to understand other's behavior/emotions towards me, but I can see just fine what other people are up to and how they'll behave.
It could be an unconscious thing. 
